Slack line carrier



p MB, 395)@ n. RcHARQs SLACK LINE CARRIER 5 Sheets-Shea?, l

Filed Nov. 30, 1951 INVENTR. @wfg/77l Richards TTORNEYJ' p w, QS@ D.Ram-mans sLAcK LINE CARRIER 5 Sheets-Sheet 2 Filed NOV. 30, 1951 PI' 10,1956 D. RICHARDS 2,741,372

SLACK LINE CARRIER Filed Nov. 30, 1951 5 Sheets-Sheefl 3 F* E.. E

"V5 /Z y- 4 April 10, 1956 D. RICHARDS 2,741,372

sLAcK LINE CARRIER Filed Nov. so, 1951 5 sheets-sheet 4 J/QVQM@ UnitedStates Patent *i SLACK LINE CARRIER Dwight Richards, Portland, Greg.,assignor to Guy F.

Atkinson Company, San Francisco, Calif., a corporation of NevadaApplication November 3l), 1951, Serial No. 259,187

S Claims. (Cl. 212-120) This invention relates generally to slack linecarriers suitable for use with cable way systems of the suspension type.

In conventional cable way systems of the suspension type a main carriercable is extended between horizontally spaced supporting towers, andserves to support and track a main operating carriage. An additionalendless cable extends between the towers and is attached to the carriagefor traversing the latter along the main cable. Also a hoist cable isextended from the cable tower to the main carriage, and is reeved oversheaves on the main carriage and on a traveling block assembly, toprovide for raising and lowering a load. Cable systems of the type justdescribed (known as Vtelphers) are used on large scale constructionprojects, as for example for transporting concrete from a batch mixer tothe various sections of a dam under construction. in the operation ofsuch cable systems that part of the hoist cable which extends from themain carriage to the cable tower becomes slack t after a load has beendischarged, and while the main carriage and the concrete hopper arebeing maneuvered back to a position for receiving another batch ofmaterial. Unless special support means is employed, excessive slack mayinterfere with operation of the system and may cause the hoist cable tobecome fouled. in the past, slack carriers have been used to providesuch support. Each carrier consists of a frame which is tracked upon themain cable and which carries one or more sheaves for engaging andsupporting the hoist cable. A plurality of such carriers are applied tothe main cable, on one or both sides of the main carriage. ln order tomaintain a desired spacing between the carriers, as the main cable istraversed between the towers, a separate button line has been employed,which is arranged to pick up the slack carriers successively, and thusdistribute them at regular intervals along the main cable. When the maincarriage is traversed over a length of main cable along which carriershave been distributed, the carriers are racked or lodged successivelyupon the advancing end of the carriage, and in position to be picked upsuccessively by the button line when the carriage is moved again in theopposite direction.

A slack carrier arrangement of the type described above has severaldisadvantages. Both pickup of the carriers by the button line, andracking of the carriers upon the advancing end of the main carriage,involveimpacts and shock forces of considerable magnitude. This places aserious limitation upon tne speed of movement of the main carriage whichcan be attained in actual practice. ln addition, it causes considerablemechanical wear and general deterioration of the equipment.

It is an object of the present invention to provide an improved slackline carrier for cable systems of the above character, which willovercome the above described disadvantages of prior arrangements.

Another objectof the invention is to provide a slack line carrierwvhichwill make possible higher speeds of operation of the main carriagewithout involving severe v impact forces.

Another object of the invention is to provide a slack line carrier whichwill automatically distribute itself along the main support cable,without the use of a button line or like positive pickup means.

Another object of the invention is to provide a slack line carrier whichwill more adequately support the hoist line, and which when a number ofsuch devices are used will cause automatic distribution over the lengthof the line extending from the main carriage to one or both of thesupport towers.

Additional objects of the invention will appear from the followingdescription in which the preferred embodiment has been set forth indetail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure 1 is a side elevational view illustrating a slack carrierincorporating the present invention.

Figure 2 is a cross-sectional view taken along the line 2-2 of Figure l.t

Figure 3 is a cross-sectional view taken along the line 3-3 of Figure l.

Figure 4 is a cross-sectional view taken along the line 4 4 of Figure 3.

Figure 5 is a schematic diagram illustrating application of a pluralityof my slack carriers to a cable hoist system.

Figure 6 is a side elevational View illustrating another embodiment ofthe invention. v

Figure 7 is an enlarged cross-sectional view taken along the line V7--7of Figure 6.

The slack line carrier illustrated in the drawing consists generally ofa frame 10 which carries the working parts. Figure l illustrates thecarrier in conjunction with three lengths of cable, namely the mainsupport cable 11, the haul or endless cable 12, and the hoist cable 13.The main cable 11 is stretched between the cable and anchor towers, andserves to support and track the main carriage of the cable system. ri`hehaul cable 12 is made endless, with its lower run attached to the maincarriage. At the anchor tower the end loop of the haul cable passes oversuitable sheaves, and at the cable tower it passes over supportingsheaves and also winch drums whereby the haul cable can be operated tomove the main carriage to any desired position between the supportingtowers. The upper run of the haul cable is not illustrated in Figure 1,and is generally at a considerable elevation above the main cable 11.

The hoist cable 13 extends from an operating winch at the cable tower tothe main carriage. It is reeved over sheaves on the main carriage, andover sheaves carried by a traveling block, whereby upon winding up orplaying out this cable from the cable tower, the load can be raised orlowered as desired. In some instances one end of this cable is deadended upon the main carriage, and in other instances it is extended fordead ending upon the anchor tower.

The frame 10 consists of side fabricated structural members l16, whichare cross-connected by the upper and lower members 17 and 18. At theupper end of the frame there is a main sheave 19, which is iixed to theshaft 21. Bearing assemblies 22 serve to journal the shaft 21 in theside structural members 16. The periphery of the sheave 19 is grooved totrack upon the',

3 beams 24 are Vseclned to the tubular Vmember 26, which is carriedl bythe shaft 27. The side members 16 of the frame have slots 23 whichaccommodate the shaft 27, and thus permit this shaft, together with thebeams 24, to move toward or away from the sheave 19. l

Suitable spring means is arranged to apply forces to Vthe extremities ofthe shaft 27, and to thereby urge the sheaves 23 against the undersideof the main cable.Y In Figure 3 of the drawing the spring means isdesignated generally at 29 and will be presently described in detail.

ln order to guide and prevent cockingl'of the shaft 27, it isV showncarried by a pair Yof guide blocks 31, which in turn engage theguideways 32. The guideways are mounted upon the side member 16, andserve to retain the shaft 27 perpendicular to a plane corresponding tothe plane of rotation of the sheave 19, while at the same timepermitting limited movement of the shaft toward vor away rorn theslieave 19. The spring means 29 serves to urge the ushaft 27 upwardly,whereby the sheaves 23 are continuously urged against the lower side ofthe main n cable at 11. The -normal position of the sheaves 23 isillustrated in Figure l. lt will be evident that the arrangement thusdescribed tends to prevent turning of the carrier about a vertical axis,and in addition tends to prevent oscillating movements in a verticalplane coincident with the main cable.

Below the sheave19, the frame supports another sheave 33 (Figure 3)which has a grooved periphery adapted to engage the lower side of thehaul cable 12. Sheave 33 is carried Vby the shaft 34, which in turn isjournaled to the frame by bearing assemblies 36.

Additional sheave means is provided for engaging the cable 12, and forretaining this cable in irictional driving relation with the sheave 33.rl`hu`s a pair of spaced paral lel beams 37 extend between the sideframe members below the'beams' 24, and serve to carry sheaves 38 thatengage the upper side of the cable 12. The medial portions of the beams37 are secured to the tube 39, whichis carried by the shaft 41." Theshaft extends through guide blocks 42, which engage the guideways 43.The extremities of shaft 41 are connected to the same spring means 29 asis employed for connection with the shaft 27.

The spring means 29 upon each side of the carrier consists in eachinstance of telescopic casings 46 and 47, which serve to house thecompression spring 48. The

casing 46 is secured to the hollow rod 49, which yin turn is secured toa hub 5l surrounding the adjacent end of shaft 27. The hollow' rod 49 isguided upon the rod 52, to which the casing 47 is attached, and which issecured to a'hub 53 upon'the adjacent end of shaft 41. lt will beevident that with this arrangement the compression springs 4S act inopposite directions upon theV telescopic casings 46 Vand 47, thus urgingthe shafts `27 and 41 in opposite directions.

At the lower end of the frame (Figures 1 and 2) there is a stirrup-likestructure 56, which can be constructed as illustrated in Figure 2. Thusthe structure includes two side members 57, the upper ends of which arejournaled by roller bearing assemblies S8 with the shaft 59.

Shaft 59 is mounted upon the lower extremities of the frame member 16. Asheave 6i) is journaled to the lower ends of members 57, and serves as asupporting sheave for the haul line 13.

A drive connection is provided vbetween vthe sheaves 19 and 33, wherebywhen relative motion occurs between the haul cable. and themain cable,vthe entire carrier is caused to move along the main cable. The driveconnection in this instance includes the two endless drive belts 61(Figure l) which engage the'rupper and lower sheaves 62 and 63. Theupper sheaves62 (Figure 3) are secured to the extremities of the shaft21, and therefore rotate with the sheave 19. The lower sheaves.v 63'areattached tothe extremities of the shaft 34, and rotate together withrthesheave 33. The proportioning of the.

Y riage to the right.

sheaves 62 and 63 determines the drive ratio established.

Automatic means is vprovided for either establishing or interrupting thedrive connection. Thus a portion of each belt 61, which extends betweenthe sheaves 62 and 63, is engaged by an idler 66 (Figures l and 4). Eachidler is carried by a shaft 67 (Figure 4), which is secured to thespaced arms 68 and 69. The arms 68 and 69 have their lower ends securedto the end portions of a shaft 71,

and this shaft in turn extends through and is secured toV Ythe adjacentbeams 37. The vfree ends of the arms 69 are attached by turnbuclrlelinks 72 to the tension springs 73. These springs are anchored to thebrackets 74, which Vare carried by the remote ends of the beams 37. Thetension springs 73 serve to urge theV idler sheaves 66 against the drivebelts 61. v

The arms 68 are connected by links 76 with the arms 77. A rocker shaft79 is carried by the adjacent ends of the beams 37 and serves to mountthe arms 77. An operating arm or lever 31 -is also fixed to the Yshaft79 and provided with a portion adapted to 'oc engaged for rorcing thearm 81 to the left as viewed in Figure-'1. The structure S3 (Figure 4)which forms a cross connection between the adjacent ends of the beams37, also forms a bolster or bumper plate 84. A similar plate 86 is shownmounted upon the opposite ends of the beams 37 (Figure l).

With the drive arrangement described above, it will be evident Vthat apositive drive is provided between ythe sheaves V62 and 63 and betweenthe corresponding cable engaging sheaves y19 and 33, for the position ofthe operating parts illustrated in FigureV Il. Under such conditionswhen the haul 'cable V,12.is pulled toward the right as viewed in Figurel, resulting rotation of the sheave 33` causes rotation of the sheave 19torrnove the entire -car- The rate of movement, relative to the rate ofmovement of the cable `12, is dependent upon the 'drive ratioestablished between the sheaves '19 and 33, and .this in turn isdetermined by the relative diameters of the sheaves 62 and 63. Whenthe'carrierengages an adjacent abutment, which may be an abutment uponuthe main carriage, for uponanother slacit carrier, arrn 81 is swungclockwise as viewed Vin vFigure l, with the result that the idlersheaves 66 are swung toward the right against the tension of the springs73, and this in turn loosens the drive belts 61 in order to permitsubstantially free slippage betweenthe belt and the sheaves 62 and 63.

The drive is now interrupted and movement of the cable 12 under suchconditions does not cause movement of Assuming that the position ofthecarriage 4 is such that it is adjacent the anchor tower, the carriers 1,2 and 3 Y will be spaced apart and distributed between thecarriageandthe cable tower. Their location will be such that they Aadequatelysupport the hoist cable 13 when this cable is slack. As the carriage 4moves to the left from the position shown in Figure 4, each of thecarriers 1, 2

and 3 also moves to the left, because of the positivev drive connectionbetween the sheaves 19 and 33 of each carrier. rate as great as that ofthe main carriage. Because of the dierent ratios employed for the driveconnections the gaps between adjacent slack carriers decrease as the imain carriagerapproaches the cable tower. If no slip- Y page occursbetween the yslack carriers and the `cables 11 and 12 the "slackcarriers will 'be racked for Ahunched together 'at the advancing end ofthe main carriage,when

However none of the carriers will move at aV the main carriage reachesits extreme left hand position adjacent the cable tower. If however someslippage has occurred in such a manner as to tend to cause one or moreof the slack carriers to slide toward the center of the system, then thedrive connections of one or more of the slack carriers are interruptedas it is engaged by another carrier or by the carriage, and this carrieris then moved in unison with the carrier or main carriage with which itmay have engaged. Por example if the main carriage engages the slackcarrier 1, before the above mentioned limiting position has beenreached, the drive connection of carrier 1 is interrupted, andthereafter carrier 1 is pushed along the cable 11 by the main carriage,until the main carriage reaches its above mentioned limiting position.When the carriage returns to- Ward the center of the system, or towardthe opposite tower, the drive connection of slack carrier 1 isimmediately reengaged, so that this carrier then again takes itsindividual movement along the main cable, to maintain a desired distancefrom the main carriage, and from adjacent carriers. If the slack carrier2 should slip toward the middle of the system, without correspondingslippage taking place in the carrier 1, then carrier 2 will be picked upand moved along in the same manner by the carrier 1, without automaticdisruption of the drive connection of carrier 1.

In the foregoing explanation reference is made to an arrangement ofslack carriers upon only one side of the main carriage. It will beevident that similar slack carriers can be used upon the other side ofthe main carriage, particularly where the hoist cableextends from themain carriage to both the anchor and cable towers.

My slack carrier has many advantages over the arrangements which havebeen used in the past. The carriers are distributed by virtue of theirdrive connections, and without the necessity of abruptly acceleratingthe successive carriers. No pick-up action is required except insofar asslippage occurs between carriers and the cables, and under suchconditions the drive connection of a carrier is interrupted so that thecarrier is free to move back to its normal position. The advantages thusdescribed make it possible for a cable way system equipped with my slackcarriers to be operated at relatively high speed, compared to the speedspreviously employed with conventional arrangements.

In the embodiment of Figures 6 and 7, the belt drive means iseliminated, and a gearing of the planetary type serves to connect thetwo sheaves which engage the main and haul cables. Also in thisembodiment the sheaves are concentric and a number of the constructionaldetails have been simplied. The main frame 91 in this instance is formedof the side vertical frame members 92, which are suitably interconnectedby cross members. The upper ends of the frame members 92 are directlysecured to the beams 93, which carry the tracking sheaves 94 forengaging the main cable 11. Beams 96 carry the sheaves 97, which engagethe cable 12. Beams 96 are connected at their ends by cross members 9S,and their central portions are pivotally secured to the blocks 101,which in turn are slidably carried by the side frame members, and areurged upwardly by the compression spring assemblies 102.

The underside of the main cable 11, between the sheaves 94, is engagedby the sheave assembly 103. Housed within this assembly there is asecond sheave 104, which operatively engages the cable 12. Both thesheave assembly 103 and sheave 104 are mounted upon a common shaft 106,together with elements of a planetary interconnecting gearing.

The sheave assembly 103 consists of two halves 103a and 1031:', whichare dished, and which have peripheral portions 107 in spaced oppositionto engage the main cable 11 and permit the cable 12 to engage the sheave104. The sheave part 103:1 is provided with a hub 108, which isjournaled by roller bearing assembly 109 to 6 the shaft 106. Hub 10s isalso secured to the hub 11i of a gear 112, and hub 111 is journaled tothe shaft 106 by the needle bearing assembly 113. An arm 114 is keyed tothe shaft 106, and a shaft 116, journaled to the free end of this arm,carries the gears 117 and 118. Gear 117 engages the teeth of gear 112.

The sheave 104 is provided with a hub 119, which is suitably journaledto the central portion of shaft 106 by needle bearings 120. The hub alsoprovides a gear 121 which meshes with the teeth of gear 118.

The hub 122 of the sheave half 103b is similarly journaled by rollerbearing assembly 123 to the shaft 106. A gear 124 secured to this hubengages a gear 126, which is attached to the shaft 127. The latter isjournaled to the free end of the arm 12S, and also carries a gear 129.Arm 128 is keyed to the shaft 106. Gear 129 engages a gear 131, which issecured to the hub of the sheave 104.

It will be evident that the arrangement described above provides twoindependent trains of gearing between sheave assembly 103 and sheave104. When the two gear trains provide different drive ratios, by virtueof the diierent dimensioning of the gears, one of the gear trains can bedisabled, as by the removal of one or more of the essential gears fromthe same. However if desired the trains can be of the same ratio andoperated simultaneously.

The ends of shaft 106 are loosely carried by the blocks 101a, and theseblocks are urged toward beams 93 by the compression spring assemblies102:1.

As shown in Figure 6, the beams 96 are shown provided with the bumperlever 133, which has its arm 134 attached to the link 136. Notchedannular members 137 are mounted upon the exterior ends of the shaft 106,and one of these members is adapted to be engaged by the sliding lockpin 138. This pin is spring urged toward engaged position and isconnected to the adjacent end of link 136.

The apparatus illustrated in Figures 6 and 7 operates as follows: Thetwo halves of the sheave assembly 103 engage and form a friction drivewith the underside of the main cable 11. The cable 12 operates throughthe slot provided between the two sheave halves 102m and 10312, toengage the sheave 104. Assuming that the right hand gear train of Figure7 is inactive, and assuming that the left hand notched member 137 isstationary by virtue of engagement with pin 138, rotation of sheave 104by movement of the cable 12 causes the sheave assembly 103 to be rotatedthrough the gear train, and at a drive ratio dependent upon the geartrain design. When the bumper lever 133 is engaged in the mannerpreviously described, the notched member 137 is released thus permittingthe shaft 106 to be free to rotate. This interrupts the drive connectionbetween sheave assembly 103 and the sheave 104, thereby securingthe'same results as interrupting the belt --drive employed in the firstdescribed embodiment.

When one desires to use the 'drive ratio provided by the right hand geartrain of Figure 7, then the left hand gear train can be disabled as bymoving one or vmore essential gears, and other gear train is madeoperative. The right hand gear train now establishes a drive of apredetermined ratio between the sheave assembly k103 and 104, when themain shaft 106 is stationary.

The embodiment of Figures 6 and 7 is advantageous in that the elementsof the gear train are completely housed within the sheave assembly 103.Thus the use of exposed drive elements such as belts and the like isobviated.

l claim:

l. A slack line carrier for cable systems of the type including a mainload carrying cable extending between cable towers for tracking a maincarriage, an endless haul cable for traversing the carriage along themain cable, and a hoist cable for supporting a load from the carriage;

the slack line carrier comprising a frame, means onY the frame fortracking the carrier on the main cable, said means including a pair ofside by side half sheave lsections disposed in spaced opposition tolrotate about a common axis, the spacing between said sheave sectionsserving to accommodate the haul cable, additional means onV the framefor continuously tracking the carrier with respect to the haul cable,said last means including another sheave disposed between said halfsheave sections and concentric therewith, drive means enclosed withinsaid sheave 'sections for operatively connecting at least one of saidsheave sections with said second named sheave member, means carried bythe frame for supporting and Yretaining the hoist cable, and means forautomatically disengaging said drive connecting means responsive toengagement of the carrier with an adjacent abutment.

2. A carrier as in claim 1 in which said last named means includesmembers disposed exterior of said sheave halves and adapted to beengaged or disengaged responsive to engagement of the carrier with anadjacent abutment.

3-. A slack line carrier for cable systems of the type including a mainload carrying cable extending between cable towers for tracking a maincarriage, an` endless haul cable for traversing the lcarriage along themain cable and a hoist cable for supporting a load from vthe carriage,the slack line carrier comprising a frame, sheave means on the frame fortracking the carrier'on the main cable including a sheave member incontinuous driving engagement with the main cable, said sheave memberbeing formed of two halves which each engage the main cable, additionalsheave means on the frame for continuously tracking the carrierwithrespect to the haul cable, said last means including another sheavemember concentric with respect to said firstV named sheave member andbeing in continuous driving engagement with the Vhaul cable, drive meansoperatively connecting said sheave member for causing movement from thecarrier along the main cable responsive to movementV of the haul cablerelative to the main cable, means carried by the frame for supportingand retaining the hoist cable,

and means for automatically disengaging said drive connecting meansresponsive to the engagement of the carrier with an adjacent abutment.

4. A slack line carrier for cable systems of the type including a mainload carrying cable extending between cable towers for tracking a maincarriage, an endless 'haul cable for traversing the carriage along themain cable, and a hoist cable for supporting a load from the carriage; aslack line carrier comprising 'a frame, sheave means on the frame fortracking the carrier on'the main cable and including a sheave member incontinuous driving engagement with the main cable, said sheave memberbeing formed of two halves which eachengage the main cable, additionalsheave means on the frame Vfor continuously tracking the carrier withrespect to the haul cable, said last means including another sheavemember concentric Vwith respect to said rst named sheave member and incontinuous driving engagement with the haul cable, drive meanscomprising planetary .gearing for operatively connecting said sheavemembers for causing movement of the carrier along the main carrierresponsive to move` ment of the haul cable relative to the main cable,means carried by the frame for supporting and retaining the hoist cable,and means for automatically interrupting said planetary ygearing inresponse to engagement of the carrier with an adjacent abutment.

5. A slack line Ycarrier -for cable systems of the type including a mainload carrying cable extending between cable towers for tracking'a maincarriage, an endless haul cable for traversing the carriage along themain cable,

and a hoist cable for supporting a 'load from the carriage;

the slack vline carrier comprising a frame, vsheave means on the Vframefor tracking the carrier on the main cable and including a drivingsheave member mounted on one side of said maingcable and a pair ofsheave members mounted on the opposite side of said main cable, Vsaidlast named sheave members serving to maintain the driving sheave memberin continuous driving engage` ment with said main cable, additionalsheave means on the frame for continuously tracking the carrier withrespect to the haul cable, said last named means lincluding a drivingsheave member mounted on one side of said haul cable, and a pair ofsheave members mounted on the opposite yside of said haul cable, thelast named sheave members serving to maintain the last named drivingsheave member -in continuous driving engagement with the hall cable,drive means operatively connecting said Vdriving sheave members forcausing movement of the carrier along the main cable responsive tomovement of the Vhaui cable relative to the main cable, means carriedYby the frame for lsupporting and retaining the hoist cable, and meansVfor automatically disengaging said drive connecting means responsive toengagement of the carrier with an adjacent abutment.

6. A slack line carrier as in claim 5 in which the twov driving sheavemembers are concentric with respect to each other.

7. A slack line carrier as in claim 6 in which the drive means comprisesplanetary gearing and in which the means for automatically disengagingsaid drive means consists of means for interrupting said planetarygearing.

8. A slack line carrier as in claim 5 in which the drive means comprisesan endless drive belt of the type adapted to be tightened to establishavdrive connection between the driving sheave members and `to beslackened for disrupting the drive connection.

References Cited in the tile of .this patent UNITED STATES PATENTS

